How long do topical corticosteroids take to work for photodermatitis?

Photodermatitis is inflammation that follows exposure to light, sometimes after contact with a product or medicine that makes skin more light-sensitive. A steroid cream reduces local inflammation; it does not remove an ongoing trigger. New exposure can keep the rash active, while lingering colour changes may remain after the itch and swelling settle.

Apply the prescribed product in the amount and frequency advised, to the affected skin only. Protect the area from sunlight with clothing and shade, and pause any suspected new fragranced or irritating product until a clinician reviews it. Do not extend treatment, cover the area tightly, or use a stronger steroid without advice. See the guide to [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/).

Arrange a review if the rash is spreading, blistering, painful, infected-looking, or not starting to settle after the prescribed course. Seek urgent care for facial swelling, breathing difficulty, extensive blistering, or skin involvement around the eyes. A clinician may need to identify a medicine or product trigger and adjust the plan.

Ask which strength is intended, how many applications are appropriate, what sunlight protection is suitable, and whether a medicine, cosmetic, or plant exposure could be contributing.